package com.shf.dao;


import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;

public class JDKProxy {
    public static void main(String[] args)
    {
//        创建接口实现类代理对象
        Class[] interfaces = {UserDao.class};
//        Proxy.newProxyInstance(JDKProxy.class.getClassLoader(), interfaces, new InvocationHandler() {
//            @Override
//            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
//                return null;
//            }
//        });

        UserDaoImpl userDao = new UserDaoImpl();
        UserDao dao = (UserDao) Proxy.newProxyInstance(JDKProxy.class.getClassLoader(), interfaces, new UserDaoProxy(userDao));
        int res = dao.add(1, 2);
        System.out.println(res);
    }
}

//创建代理对象代码
class UserDaoProxy implements InvocationHandler{
//    1.把创建的是谁的代理对象,把谁传递过来
//    有参数构造传递
    private Object obj;
    public UserDaoProxy(Object obj){
        this.obj = obj;
    }

//    增强的逻辑
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
//        方法之前
        System.out.println("方法之前执行..."+method.getName() + "传递的参数"+ Arrays.toString(args));

//        被增强的方法执行
        Object res = method.invoke(obj, args);

//        方法之后
        System.out.println("方法之后执行"+obj);
        return res;
    }
}